17
"
 Fancy indexing allows us to select entire rows or columns out of
 order.
 Fancy indexing allows us to grab any row using its index, let’s
 grab row 1, 2 and 3.
 We need to pass in a list of required rows in square brackets:
 Let's suppose a 2D array named 'arr':
 ----------------------------------------------------------------
 arr[[1,2,3]]
 output: array([[1,1,1],
                [2,2,2],
                [3,3,3]])
 ----------------------------------------------------------------
 Now with columns:
 ---------------------------------------------------------------
 arr[:,[3,2]]
 output: array([[3,2],
                [7,6],
                [1,0],
                [0,1]])
 -----------------------------------------------------------------
 "